A numerical analysis of load sharing and implant positioning on the stress distribution in a prosthetized tibial bone

The aim of the present work was to estimate the effect of prosthesis positioning and of load sharing on the VonMises stress distribution in a tibial bone. The analysis was focused on three main bone regions: the medial periprosthetic region, the lateral periprosthetic region and the bone-prosthesis interface region. A three-dimensional static finite element analysis of a tibia with a cementless baseplate was performed. The geometric model of the bone was based on a standard tibia model in which a commercial knee prosthesis was implanted. In this study eleven different load conditions and nine prosthesis positions were considered. The FE analysis shows an influence of baseplate positioning, and also of load sharing, on the average Von Mises stresses in the considered regions. The average stress in the bone prosthesis interfacial region was not sensitive to implant position, and was moderately sensitive to load sharing. The average stress in the lateral periprosthetic region presented linear relationships with implant positioning and load sharing. The average stress in the medial periprosthetic region presented a similar trend as the lateral region regarding load sharing, but it showed a non linear relationship with implant positioning.status: publishe